Discovery Arrival Delayed; Crew Does Science

The Expedition 20 crew members worked with a variety of science experiments aboard the International Space Station Thursday as they continued to prepare for the arrival of space shuttle Discovery.

The launch target for STS-128 is Friday at 11:59 p.m. EDT as engineers evaluate a liquid hydrogen valve that developed problems during tanking operations Tuesday.

Expedition 20 Flight Engineer Michael Barratt reads a checklist while working with the Synchronized Position Hold, Engage, Reorient, Experimental Satellites experiment in the Destiny laboratory of the International Space Station. Credit: NASA

Discovery is carrying more than seven tons of supplies, science racks and equipment, as well as additional environmental hardware to sustain six crew members on the orbital outpost. The shuttle also will deliver the newest Expedition crew member, astronaut Nicole Stott, for a three-month stay aboard the station.

Flight Engineer Tim Kopra continued with departure preparations as he will be returning home aboard Discovery. He arrived at the station on July 17.

Flight engineers Bob Thirsk and Frank De Winne recorded educational video demonstrations designed to inspire the next generation of space explorers. The demonstrations focused on surface tension and wave motion properties in microgravity conditions. These videos recorded by crews living and working aboard the station are used in developing curriculum support materials for distribution to educators internationally.

Flight Engineer Mike Barratt, along with Kopra, worked with the Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) experiment. SPHERES is comprised of three free-flying spheres that fly within the station, performing flight formations. Each satellite is self-contained with power, propulsion, computers and navigation equipment. The results are important for satellite servicing, vehicle assembly and formation flying spacecraft configurations.

Meanwhile, in the Russian segment of the station, Commander Gennady Padalka and Flight Engineer Roman Romanenko took various environmental measurements and cleaned fan guard screens.